[llvm] [workflows] Build a container for running CI on github actions (PR #75286)

[Aiden Grossman via llvm-commits]

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+FROM docker.io/library/ubuntu:22.04
+
+# swig is needed for lldb docs.
+
+# abi-dumper, autoconf, and pkg-config are required for the abi-dump workflow.
+# abi-compliance-checker is needed for the abi-compare workflow.
+# python3-setuptools and python3-psutil are required for the release-lit task.
+# Need to install curl for hendrikmuhs/ccache-action
+# Need nodejs for some of the GitHub actions.
+RUN apt-get update && \
+    apt-get install -y \
+    abi-compliance-checker \
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boomanaiden154 wrote:

I'm assuming one of these packages pulls in a `gcc` based toolchain? It'll be needed for the documentation tests.

https://github.com/llvm/llvm-project/pull/75286